Thursday, May 2, 2013

Raw photoastronomy with the HS25EXR, Night 1

We are starting a series of articles on simple photoastronomy with the HS25EXR camera.
This relatively inexpensive bridge camera features a maximum zoom of 30x, greater than the cheap normal 7x plastic binoculars sold in stores. Such magnification naturally raises expectations as its use in simple photoastronomy, dispensing with low power finder scopes.

One essential equipment we need to have is a tripod. One can obtain a cheap aluminium tripod from CDR-King but they are not really high quality stable platforms, but what can we do? My tripod is the Model TPOD-003-CO which set me back for 600.00 pesos! Worse the tripod carries no WARRANTY of any kind from the CDR-King store at Gaisano Mall in Bacolod City.

Of course a telescope will simplify a lot of things and a refractor telescope is available from,..;, from CDR-KINg! This has eyepieces for 100x and 200x viewing. Unfortunately it is out of stock from the Gaisano Bacolod branch.

The moon should be the first object one should try to capture. You might think that as it is the brightest object in the night sky, it should be easy to photograph, bit it is a big Not! Automatic modes would only show a bright orb without the details, showing your that our eye has that amazing ability to adjust for glaring objects! Please visit our articles about photographing the moon.

To recall , the HS25EXR camera has a manual mode, offering user settings of exposure times up to 30 seconds or lower values depending mostly on the ISO settings.

Here are two photos taken at 9:45 pm, May 2, 2013.

10s, f/2.8, ISO 100, 9:41PM, May 2, 2013.

15s, f/7.1, ISO 200, May 2 2013

Always start at 1.0 magnification, capture a target on the screen and slowly magnify it thru the zoom barrel.

I dont know the name of the object in the second photo but we can with the help of astronomical software such as Kstars and Celestiao, pinpoint the names and locations of interesting celestial objects at the approximate times of viewing and general directions. I can still recognize the constellation of Orion, the big Dipper but not the others.

We need to adjust our eyes to the darkness. Turn off ambient lighting as much as possible. The reflections will be distracting and may be captured by the camera as noise.

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